492 



Antennae less than one and a half times as long as head and thorax 

 together. Thorax distinctly produced anteriorly ; pronotum narrow, 

 not continued to upper margin of mesonotum. Abdomen slender ; 

 hypopygium as in Figure 8, Plate XXXVL Legs without long hairs ; 

 basal joint of fore tarsi more than one half longer than fore tibiae 

 (26: 16). Cross vein almost at middle of wing; cubitus forking 

 slightly beyond cross vein; third vein ending distinctly before curve at 

 apex of wing; surface hairs of wing pale and sparse. 



Length, 2.5 mm. 



Type locality, shore of Lake Michigan at South Haven, Mich., 

 July 14, 1914 (C. A. Hart). 



Female and early stages unknown. 



This species bears a close resemblance to pusio, but is distinguish- 

 able by the entirely black thorax, the form of the hypopygium, and 

 the length of the basal joint of the fore tarsi in comparison with that 

 of the fore tibiae. 



9. Tanytarsus obkdiens Johannseu 



Tanytarsus ohediens Johannsen, Bull. 86, N. Y. State Mus., 1905, p. 286. 



Male. — Black, slightly shining. Head brownish black; antennae 

 fuscous, scape and extreme base of flagellum yellow, plumes fuscous, 

 whitish at the tips. Mesonotum with very faint pruinescence on area 

 between the vittae ; anterior lateral angles of thorax sometimes yellow- 

 ish; scutellum varying from brown to yellowish. Posterior margins 

 of abdominal segments and the lateral margins on posterior half yel- 

 low; hypopygium blackish brown. Legs almost white, bases of mid 

 and hind coxae blackened. Wings whitish, veins pale yellow ; surface 

 hairs yellow. Halteres yellow, knob white. 



Frontal tubercles absent; antenna; about 1.5 as long as head and 

 thorax together; palpi longer than height of head, apical joint dis- 

 tinctly longer than subapical. Pronotum linear on upper half ; meso- 

 notum produced anteriorly. Hypopygium as in Figure 9, Plate 

 XXXVL Legs long and slender, fore tarsi without long hairs, basal 

 joint about one fifth longer than fore tibiae. Third vein ending slightly 

 farther from apex of wing than does fourth ; cubitus forking below 

 cross vein. 



Female. — Agrees with the male in color except that the antenn;e 

 are yellow and the abdominal segments have narrow pale posterior 

 margins. 



Length, 3.5-4.5 "im. 



Illinois localities, Lilly and Havana. June (C. A. Hart). 



